/*
 * Copyright (c) 2007-2008, Thomas Krause (tho.krause@gmail.com)
 * 
 * All rights reserved.
 * 
 * Redistribution and use in source and binary forms, with or without modification,
 * are permitted provided that the following conditions are met:
 * 
 *     * Redistributions of source code must retain the above copyright notice,
 *       this list of conditions and the following disclaimer.
 *     * Redistributions in binary form must reproduce the above copyright notice,
 *       this list of conditions and the following disclaimer in the documentation
 *       and/or other materials provided with the distribution.
 *     * Neither the name of gidoo nor the names of its contributors may be used to
 *       endorse or promote products derived from this software without specific
 *       prior written permission.
 * 
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
 * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

package org.gidoo.cms.helper;

import java.io.UnsupportedEncodingException;
import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;

/**
 * Class for cryptographic functions.
 * @author thomas
 */
public class Crypto 
{
  public static final String SALT = "&f2S2?d%sxaA...%%SY42Y!a";
  
  /**
   * Hashes a string using MD5. <br>
   * <b>MD5 is insecure. Use {@link #calculateSHAHash} instead.</b>
   */
  @Deprecated
  public static String calculateMD5Hash(String s) throws NoSuchAlgorithmException, UnsupportedEncodingException
  {
    MessageDigest md = MessageDigest.getInstance("MD5");
    md.update(s.getBytes("UTF-8"));
    byte[] digest = md.digest();

    String hashVal = "";
    for(byte b : digest)
    {
      hashVal += String.format("%02x", b);
    }
    
    return hashVal;
  }
  
  /** Hashes a string using SHA. */
  public static String calculateSHAHash(String s) throws NoSuchAlgorithmException, UnsupportedEncodingException
  {
    String withSalt = SALT + s;
    MessageDigest md = MessageDigest.getInstance("SHA");
    md.update(withSalt.getBytes("UTF-8"));
    byte[] digest = md.digest();

    String hashVal = "";
    for(byte b : digest)
    {
      hashVal += String.format("%02x", b);
    }
    
    return hashVal;
  }
}
